Patent GB-773999-A (GB)
Title: Improvements in or relating to improved mineral-base lubricating oils and methods for using same
IPC: C10M165/00
Filed: 1954-07-13
Abstract: A lubricating composition which when employed as the lubricant in an internal combustion engine, has little tendency to produce combustion chamber deposits which contribute to an increase in the octane number requirement of the gasoline fuel employed, comprises a major proportion of mineral lubricating oil and a minor proportion of one or more of the additives listed below, the total composition having a resinification index (i.e. the proportion of solid combustion residue as determined by a specified procedure) of less than 20 mg./5 gms. The additives are oil-soluble viscosity index improvers, detergents or oxidation inhibitors chosen from (1) polyolefins having a molecular weight above 5,000; (2) phosphosulphurized hydrocarbons which may have been treated to reduce acidity; (3) metal petroleum sulphonates; (4) metal salts of alkyl phenolsulphides; (5) metal dialkyl phosphates or thiophosphates and (6) polymers of esters of unsaturated carboxylic acids.  Ingredient (1) may be a polymerized C3-C5 olefin or a polyalkylstyrene, while ingredient (2) may be produced by the action of a phosphorus sulphide or other combination of phosphoros and sulphur or a paraffin, an olefin or olefin polymer, a naphthene, or aromatic hydrocarbon, a terpene, a hydrocarbon resin or a petroleum lubricating oil.  The acidity of the phosphosulphurized material may be reduced by estrification (e.g. by reaction with esters, alcohols or phenols), by neutralization (e.g. by reaction with basic metallic compounds, ammonic or organic nitrogen bases) or by reaction with such materials as olefins (e.g. diisobutylene) or dipentene. Neutralization may be followed or preceded by treatment with steam.  Ingredient (6) may be a polymerized ester of methacrylic acid or a fumarate-vinyl-acetate copolymer.  The mineral lubricating oil may be a refined petroleum distillate and/or a refined cycle stock obtained from the catalytic cracking of a petroleum fraction.  Other lubricating oils may be present in the lubricating composition, for example synthetic hydrocarbon oils (e.g. polymerized olefins and oils obtained from coal or shale or from the reaction between hydrogen and oxides of carbon), ester oils (e.g. complex esters, and esters formed between monohydric alcohols and dicarboxylic acids, particularly di - 2 - ethyl - hexyl sebacate and di-C8 oxo alcohol sebacate), polyalkylene oxide oils, complex formals, and mercaptals and their esters.  The lubricating compositions may contain additional ingredients such as pour point depressants (e.g. chlorinated wax-naphthalene condensation products and polymers and copolymers of unsaturated esters), anti-rust agents (e.g. partial esters of polyhydroxy compounds such as oleates of sorbitan or polyglycerols, esters of the trimer of ricinoleic acid, alkyl phosphoric acids and acid phosphates), dyes, oiliness agents, plasticizers, defoamers and extreme pressure agents. The lubricating compositions are preferably employed in engines burning a gasoline having a resinification index below 40 mg./200 gms.  Such a gasoline may be formulated from two or more of straight raw petroleum distillates, alkylates (prepared by the alkylation of olefins with isoparaffins), hydroformed or reformed gasolines, and catalytically cracked naphthas.  The gasoline may also contain lead tetraethyl, scavenging agents, antioxidants, gum inhibitors, solvent oils, rust inhibitors and metal deactivators. Suitable scavengers are ethylene dibromide, ethylene dichloride, hexachlorobutadiene, dibromoxylenes, dibromotoluenes and 2, 4 dichlorotoluene.  In the examples, lubricating compositions are described which consist of (a) refined petroleum lubricating oil distillate and polyisobutene (molecular weight about 15,000), with or without P2S5-treated polybutene or the guanidine potassium, or barium salt of P2S5-treated polybutene, or a blend of P2S5-treated alpha-pinene and the guanidine or barium salt of P2S5-treated polybutene; (b) refined petroleum lubricating oil distillate and a polymerized C0-C10 alcohol ester of methacrylic acid; (c) refined petroleum lubricating oil distillate, P2Sn-treated alpha-pinene, mixed calcium and barium salts of tert.-octyl phenolsulphide and alkaline calcium petroleum sulphonate and (d) cycle stock from the catalytic cracking of gas oil and polyisobutene (moleculear weight about 15,000).  In further examples, gasoline compositions are described consisting of isopentane, catalytic and virgin naphthas and tetraethyl lead, together with either a blend of ethylene bromide with ethylene chloride or a mixture of monobromoxylenes.